Switch mechanism



ATTORNEY A- T. TWISS SWITCH MECHANISM Filed June 18, 1927 mwl Mr E W 4NM M Aug. 23, 1932.

WITNESSES: 4 1% I Patented Aug. 23, 1932 UNITEDTSTATETS PA ENT OsFFICE:

ALFRED T. TWISS, or rnArronn, :PENNsYLvANIA, AssieNon ro WESTINGHOUSEELEC- 'rnrc -& MANUFACTURING ooivrr NY, conronArron or PENNSYLVANIAswrron. MECHANISM 7 Application filed June 18 1927. 'Serial No. 199,679.

My invention relates to switch mechanisms 7 and particularly that typeknown as disconnecting switches- Disconnecting switches of this typegenerally comprise a base member, apair of spaced insulators, terminalmembers for line Wires disposed on the insulators and: a flexible shuntfor making and breaking the connections between the terminals. A pairotlinks are usually provided for supporting the flexible shunt, thesupporting links being pivotally connected to one of the spaced;insulators at one of its ends, and a movableinsulator {or supporting itsother end and adapted to connect the flexible shunt with the terminaldis.- posed on] the other spaced insulator. The movable. insulator isgenerally rotatably mounted midway between the spacedinsulators andadapted to rock to andtrom a position adjacent one of the insulators.This construction is undesirable in View of the strain on the insulatorcaused by the rocking movement about its pivot.

It is an object of my inven'tlon'top'rovide a disconnecting switchofthis type having a movable insulator mounted-in such-a manner as tomaintain it in perpendicular relation with the base member at alltimes,andv to cause such strain as the insulator:may be subjected to inbreaking ice-seals on the switch jaws to be applied in a directionsubstantially parallel to its axis thus preventing the insulator'frombeing subjected to shear.- ing by strains in a direction angular-to itsaxis. 4 A It is another object of my inventionfto provide a switchmechanism of thistype, whereby the movable insulator is moved to andfrom its closed position in such a manneras to make possible the"construction of the electrical shunt of material having sufiicientstiffness to be self-supporting, thereby eliminating from the structurethe usual links provided for supporting the shunt. 1 5

It is a further obj ect of my invention to provide a switch mechanism ofthis type having means for breaking a corrosive seal or a coating of icethat may form aboutthe switch,

.and interfere with, the opening movement thereof.

These and other'objects that may be made apparent throughout the furtherdescription of my invention are attained by means of; the apparatushereinafter described and illustrated in the accompanying drawing,

wherein A a The single figure is a side elevational view of adisconnecting switch embodying my invention, I the disconnecting switchbeing shown in its closed position by heavy lines, in its open positionby broken lines and in a fragmentary view of; a mid-position by dottedlines. l

j My invention comprises, in general, a base member 1, a pair of spacedinsulators 2 and 3, terminal plates land 5 supported by the spacedinsulators 2 and 3, respectively, line conductors 6 and 7 connected tothe respective terminal members 4 and 5, switch jaws 8 disposed on theterminal member 4:, a movably the insulator mounted insulator 9 forsupporting a contact 7 Qcom'prises an insulator seat 14 extending insubstantially parallel relation 'to the base member 1', a pair ofsubstantially parallel linkmembers 15 and 16,, the, members 15 and 16each having "one end pivotally connected to an end ot'the seat'member'Mby means of pivots 17 and 18, respectively, and their other endspivotally connected to the base'member 1 by means of pivots 19' and 21,respectively.

The link member 16 is provided with an eX; tension 22 adapted tocooperate with an actuating mechanism23 for the mechanism 13.

The link 15 is provided with a slot 2 1,in which the pivot 17 isslidably disposed, thereby providing a limited amount of lost motionlongitudinally. of the link 15. As may be seen from the drawing, themechanism 13 is so disposed that, when the switch is closed,

the link-16 extends approximately along a straight line connecting theengaged contacts and the pivot 18.

In operating my invention from its closed position, as shown by theheavy lines 1n the drawing, the actuating mechanism 23 moves theextension 22 downwardly, turning the link member 16 in clockwisedirection. The movable contact unit comprising the contact 11, theinsulator 9, and the seat member 1a is held at only one place, namely,at the engaging contacts 8 and 11. The force applied by the link member16 at the pivot 18, which force is at right angles to a line connectingthe pivots 18 and 21, will also be "atapproxt mately right angles to aline extending from the engaged contacts 8 and 11 to the pivot 18.Consequently, the movable contact unit will be moved angularly about theengaged contacts 8 and 11, the leverage action resulting in a tremendousforce which will loosen any corrosive seal or ice coating that may haveformed on the contacts.

The angular movement of the movable contact unit continues until thepivot '17 engages the inner end of the slot 24. The left hand end of theseat member 14 is thereafter forced to move upwardly as it moves to theright, so that angular movement about the'engaging contacts isterminated and the movable contact unit is maintained in approximatelythe same angular position and moved to the open positionshown in dot anddash lines.

Since the mechanism is arranged in the form of a parallelogram, itwill'm a'intain the seat member 14 in substantially horizontal positionparallel to the base member and the insulator 9 in substantiallyvertical position throughout its movement. These positions are notmaintained exactly, however, since the initial angularmovement'necessarily changes the angular positions to a slight extent.

As may also be seen from thedrawing, the weight of the insulator tendsto maintain the disconnecting switch in either its open and closedposition, as the case may be.

Arcing horns 25 and 26 are provided on the terminal member 4 and thecontact member 11, res'pectively,'and I have designed the arcing horns25 and 26 so as to'limi't the :arcing period when opening or closing thedisconnecting switch to a'minimum. It can be seen from the drawing thatthe, arcing horns start immediately to; separate after the main contactspart as shown by the dotted lines in the drawing, the various parts ofthe switch being so designed as to cause the are thereafter to be drawnbetween the arcing horns and protect the other parts of thedisconnecting switch. 7

Accordingly, I have provided a disconnecting switch comprising a basemember supporting a pair of spaced insulators, terminal members disposedon the insulators, a flexible shunt for electrically connecting theterminals, one end of theflexible shunt beingcarried by a movableinsulator, a mechanism for supporting and actuating the movableinsulator so that the movable insulator will be maintained in a positionperpendicular with respect to the base member at all times, a slotprovided in said mechanism for causing a slight rocking action of thecontact member during the initial opening movement of the disconnectingswitch, and a pair of arcing horns for cooperating in such a manner asto limit to a minimum the period of arcing when closing or opening thedisconnecting switch. The construction of this disconnecting switchpermits the use of shunts of heavier structure than has heretofore beenpracticable in view of the stresses caused by the bending of the shunt.The structure in my invention minimizes the stresses incident to thebending of the shunt, inasmuch as it merely displaces its normal bendfrom one position toanother.

While I have illustrated and described but one embodiment of myinvention, it will be apparent to those skilled in the artthat varioi'ischanges, modifications, substitutions, additions, and omissions may bemade in the apparatus without departing from the spirit and scope oftheappended claims.

I claim as my invention:

1. A circuit interrupter provided with separable contactmembers--ri1gidly supported upon stationary and movable insulating members,mechanism for actuating and for retaining said movable insulating memberin substantially vertical positionduring its movement and meanstorti'lting said movable insulator and, therefore, said attached contactmember at the initial movement of separation of the contact members.

2. A circuit interrupter provided with separable contact "membersrigidly supported upon stationary and movable insulating members, alinkage mechanism for actuating and for retaining said movableinsulating member in substantially vertical position during its movement'one of thelinks of said mechanism having a. slotted connection wherebythe insulator carrying the movable contact 'member is tilted during theinitial movementl-ofseparation of said contact members. I

8. In an electric switch, the-combination of a fixed contact, a movablecontact, a device 'formoving said movable contact'comprising fourmembers pivoted to each other in "approximately the form of aparallelogram'and including a stationary base member and an oppositemember which carries the movable contact, the pivotal'connection betweenthe contact-carrying member and one oi"? the adjacent members having a.lost motion, and means for actuating sa-id contact-moving device,whereby, in opening the switch, the blade carrying member is first moved'a-ng-ularly about the engaging contacts to loosen the same in the eventthey have been frozen to each other before moving the movable contactbodily away from the fixed contact.

4. In an electric switch, the combination of a pair of contacts one ofwhich is movable into and out of contact with the other, a memher forcarrying said movable contact, a stationary member, a first and a secondlink member each pivoted to'the contact carrying member and to thestationary member in approximately the form of a parallelogram and withthe first link extendingapproximately along a straight line extendingbetween its pivotal connection with the contact carrying member and thecontacts in engaged position, the second link having a longitudinal slotin which the pivotal connection with the blade carrying memberisreceived to provide a lost motion between the blade carrying memberand the second link, and actuating mechanism connected to the firstlink, whereby, in opening the switch, the lost motion permits the firstlink to move the blade carrying member angularly about the engagedcontacts for breaking any corrosive or ice seal that may have formed,after which the movable contact is moved bodily away from thecooperating contact andis maintained substantially in a given angular.position.

In testimony whereof, I have hereunto subscribed my name this 4th day ofJune,

ALFRED T. TWISS,

